Designs of modern processing systems face an ever increasing demand for reduction in power and energy. This is particularly seen in the realm of mobile and handheld devices which require extended battery life. One significant source of power consumption in these devices lies in their clock distribution networks and systems.
Conventional clock distribution networks include resonant clocking mechanisms which may use several levels of clock drivers to charge an inductor-capacitor (LC) tank. The LC tanks can store the energy supplied by the clock drivers and recirculate the energy into the clock distribution network during charging and discharging cycles of the clock distribution network. The efficiency of the LC tanks is conventionally measured in terms of the quality factor (or “Q factor”) of the inductor L. In general, as the Q factor increases, the LC tank is more efficient with regard to its capacity to store and recirculate energy.
Conventional clock drivers drive a supply current into the LC tank at each clock phase of a system clock. In conventional designs, the drive strengths of the clock drivers in the various levels are reduced in an effort to reduce energy consumption of the clock distribution network. While reducing the drive strength in this manner may reduce the amount of energy consumed by the clock drivers, the conventional clock drivers do not efficiently utilize the energy that is recirculated by the LC tanks.